Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Dell U4919DW / MacBook pro 5k issue

Hi,


I have just purchased the Dell U4919DW monitor to use with my early 2018 MacBook Pro 13", but unfortunately I cannot choose full resolution 5120x1440 in the settings, max is 3840x1080. I have tried the app SwitchResX to manually set the 5k resolution without luck, only scaled.


From this link I read about my MacBook before purchasing the screen that:

"this model supports a maximum resolution up to 4096x2304 at 60 Hz at millions of colors on two external displays or a single external display at a maximum resolution up to 5120x2880 at 60 Hz at over a billion colors via Thunderbolt 3 (USB-C)."

MacBook Pro "Core i5" 3.1 13" Touch/Mid-2017 Specs (Mid-2017 13" (Touch Bar), MPXV2LL/A*, MacBookPro14,2, A1706, 3163): …


My MacBook Pro has 4 USB-C ports, I'm using the left ones which operate at full speed (right ones are reduced).


Why can't I get full 5k resolution? Is it an issue with the MacBook, the connection, the screen or perhaps an iOS issue?


Additional links with information on the screen:

https://www.dell.com/support/article/dk/da/dkdhs1/sln314416/dell-u4919dw-system- requirements-and-supported-configuration…

https://www.dell.com/support/article/us/en/19/sln314339/dell-u4919dw-monitor-usa ge-and-troubleshooting-guide?lang=en#Usi…

https://www.dell.com/en-us/shop/dell-ultrasharp-49-curved-monitor-u4919dw/apd/21 0-arnw/monitors-monitor-accessories

MacBook Pro TouchBar and Touch ID, iOS 12.1

Posted on Nov 21, 2018 11:09 PM

Reply
682 replies

Jan 9, 2019 4:47 AM in response to marino389

So here's an interesting twist. According to this page, the MacBook Pro 2016 and later is compatible with the 27-inch LG UltraFine 5K Display. Here's what's interesting. I emailed LG and asked whether that particular monitor was SST or MST. And they replied that it is SST. So apparently not all SST monitors are created equal. Wondering whether I missed a small detail, or whether Apple chose to override the SST limitation and make it compatible with this specific LG monitor. See their email below...


Dear Valued LG Customer,


  

Reply to Your Inquiry


Hi John, we highly value your overall experience to be as seamless as possible. I am more than happy to assist you today. Let me provide the right information that you need about your inquiry. We have checked our support system and the 27MD5KA-B is SST monitor. Thank you, John. Have a great day! 


I hope this information has been helpful in addressing this matter. Should you have any further inquiries or clarifications, please do let us know and we'll be glad to help out. You may contact us again via Email, Live Chat, or Phone by calling 1-800-243-0000. 


Thank you for contacting LG. 



Sincerely yours, 

Belle 


LG Email Department 

Toll Free number: 1-800-243-0000 

LGEAI | Customer Interactive Center 

Monday- Sunday



May 16, 2019 2:55 AM in response to kanonendk

I have the same problem (only getting 3840x1080 without a third party app, and only able to get scaled 5120x1440 - i.e. blurry, not truly 5120x1440) on a Macbook 12" Retina from 2017.


This laptop supports one external monitor 4096x2304@60hz (at the same time as the native 12" display) according to Apple's specification pages: https://support.apple.com/kb/sp757?locale=en_GB


I don't know how to reason about this. 4096x2304 is more pixels than 5120x1440. But 5120 is a wider resolution - maybe that is what causes the problem? It is true that the specification states "up to" 4096x2304. Maybe that is to be interpreted as up to 4096px on the width, and up to 2304px on the height, instead of up to 4096x2304 ( =9,437,184 ) pixels in total. 5120x1440 = 7,372,800 pixels is a lower total amount of pixels, but the greater width (5120 > 4096) is maybe the thing that isn't supported?


But then at least the people having a Mac Mini 2018 should get it to work, because the specification pages for that model says it supports up to 5120x2880@60hz. https://support.apple.com/kb/SP782?locale=en_US

So I guess it is a problem with the specific solution 5120x1440.


Have only tried with the USB-C cable coming with the Philips 499H9P monitor.


Have tested the monitor with another PC running Windows 7 and it works flawlessly (looks gorgeous). Just had to plug and play. However, the PC does have a dedicated graphics card, but no USB-C port, so I used the DP-DP cable that came with the monitor.



Aug 16, 2019 3:40 AM in response to kanonendk

Hi there!


I just phone called Apple to ask whether this was a known issue that will be fixed when the next MacOS comes next month. Unfortunately he could neither confirm it was a known issue, nor that it will be fixed. We just had to wait and try.


But we can hope for a fix in the next MacOS. If you sign up for the Apple Beta Software Program (free and open for everyone) https://beta.apple.com/sp/betaprogram/ you are able to install the latest beta of the coming MacOS Catalina.


Can you or someone else in this thread check if the full resolution is working with the current beta? I have the beta installed, but I have not bought the screen yet because of those problems. If the beta does not work with the monitor it is possible to revert back to the stable MacOS you had.

Sep 4, 2019 6:40 PM in response to sasaforic

I wonder if that is really something Apple would / will do? I'm highly doubtful.

sasaforic wrote:

https://discussions.apple.com/content/attachment/881accb2-c152-4142-bc8d-8d798f1d89e9

After sending a macOS Catalina beta feedback with multiple screenshots and explanations with the same issue with the same monitor, my Feedback was updated to Potential fix identified.

Hopefully it will be solved and we can have a full resolution with new OS.


Oct 16, 2019 4:00 PM in response to kanonendk

I recently ran into this with:

MacBook Pro 15-inch 2018 - V10.14.6 (staying away from Catalina for now)

Samsung 49" 5120 x 1440 https://www.samsung.com/levant/monitors/c49rg9/


Initially tried with a USB-C to HDMI (multi-port) that I already had on hand

https://www.apple.com/shop/product/MUF82AM/A/usb-c-digital-av-multiport-adapter

It displayed at full resolution, but everything was pink.


Picked up a USB-C to HDMI 4k - specifies "resolution up to 3840 X 2160 @ 60Hz", but I like to live dangerously.

https://en.j5create.com/products/jcc153g

With the internal macbook display on, it displays at 3840 x 1080 @ 60Hz.

With the macbook closed, it displays at 5120 x 1440 @ 100Hz


Attemped SwitchRex - it just scaled the resolution, which made text blurry.

For now I'm going to close it and hope a fire doesn't start. Also posted a question to a product to see if an answer comes back via that avenue - https://www.apple.com/us_edu_194934/shop/product/HLR62ZM/A/moshi-usb-c-to-displayport-cable

Dec 12, 2019 8:11 PM in response to askingretail

Follow along:


There was a post at:

https://discussions.apple.com/thread/8641919?answerId=251185930022#251185930022

saying there was no override for the LG 49BL95.


I replied with:

https://discussions.apple.com/thread/8641919?answerId=251772844022#251772844022

saying that now there is a new override in 10.15.2 for the LG 49BL95 that might fix the problem.


The reply after that said it works for the LG 49BL95.



There was a reply to that at:

https://discussions.apple.com/thread/8641919?answerId=251773068022#251773068022

saying it didn't work with the Dell U4919DW.


I replied with:

https://discussions.apple.com/thread/8641919?answerId=251777696022#251777696022

saying that to make it work for the Dell, a copy of the override that was made for the LG has to be created for the Dell.


More info at:

https://gist.github.com/joevt/32e5efffe3459958759fb702579b9529


Dec 13, 2019 5:02 AM in response to joevt

joevt,


Thanks for your reply here...

https://discussions.apple.com/thread/8641919?answerId=251777696022#251777696022


I'll confess that I'm a bit nervous to start editing that type of information when I know nothing about using scripts or editing system files. I'm afraid I'd make a mistake and not know how to fix it.


Has anyone successfully implemented joevt's instructions so that the U4919DW works at full resolution? A success story would be helpful to see before I try and implement.

Dec 16, 2019 9:48 AM in response to martin243

martin243 wrote:

I'm connecting to the LG via USB-C. Try going to the Preferences -> Displays and Option clicking on the Scaled radio button option. You will get a list of resolutions. The top of my list had 3840x1080, but it now has 5120x1440 as below...


https://discussions.apple.com/content/attachment/8bd14847-272d-4fee-87ff-aaebead20ca0


Martin,


Are you getting this resolution with a MAC MINI???? or are you getting this resolution with a MBP 15/16". This thread is for issues with the Mac Mini (intel GPU). If you are talking about this on a MBP 15 / 16 please post to a different thread!!!

Dec 18, 2019 12:40 AM in response to darenjacobs

That's a good question. The MBP 13" and Mac mini 2018 use Intel graphics instead of AMD graphics.


We know that Intel graphics can have a frame buffer as large as 6720x3780 to support HiDPI mode of 3360x1890. But what about the actual DisplayPort signal? Intel graphics supports DisplayPort 1.2. DisplayPort 1.2 should allow any resolution that uses less bandwidth than 17.28 Gbps (720 MHz for 8bpc, 576 MHz for 10bpc). Here's some examples:

5120x2880@60Hz (938 MHz - too much, but 45Hz is only 699 MHz 8bpc)

5120x2160@60Hz (703 MHz 8bpc - might be too close to 720 MHz 8bpc limit?)

4096x2304@60Hz (605 MHz 8bpc)

3840x2160@60Hz (533 MHz 10bpc)

5120x1440@60Hz (469 MHz 10bpc)


Can the Intel graphics support resolutions wider than 4K? Even if the total number of pixels is less than 3840x2160, such as 5120x1440?


I don't have a LCD display wider than 3840 but I do have a CRT. With a CRT, the only limit for the width is the pixel clock of the DAC. I have a USB-C to VGA adapter which can do 330 MHz but macOS limits it to 160 MHz for Intel graphics. There's a patch for that:

https://github.com/Floris497/mac-pixel-clock-patch-V2/issues/323


I was able to create a resolution of 4096x1216@48Hz (GTF timing, 327.72 MHz) which works.

Then I tried 4104x1216@48Hz (GTF timing, 328.33 MHz). macOS would not allow it, even if it does work with my CRT.


Is the limit in the macOS drivers? I checked Windows. The Intel Graphics Control Panel would not allow > 4096 width. It says "The custom resolution exceeds the maximum bandwidth capacity." even if I half the bandwidth (24 Hz which is allowed by resolutions ≤ 4096 pixels wide).


So it seems the limitation is in the Intel graphics hardware. You can't get more then 4096 wide unless you use a dual-cable display or a dual-link SST display. Seems Apple rewrote their "Use 4K displays, 5K displays, and Ultra HD TVs with your Mac" support document and removed all mention of SST, MST, and dual-cable (now it's called "Use external monitors with your Mac")

https://support.apple.com/HT202351


I suppose they may have decided to write a separate document for each computer:

https://support.apple.com/en-ca/HT208366

While it mentions 5120x2880@60Hz, it should say that it must be a dual-link SST display.


Dual-link SST (as well as SST and MST) are mentioned in:

https://support.apple.com/en-ca/HT208366


Dec 28, 2019 8:27 PM in response to Mister_Highping

Your HDMI adapter (using a Parade Technologies ps176 I think) is only using two lanes of DisplayPort 1.2 so it can't do more than 4K@30Hz or 2560x1440@60Hz. Is it the older version of the Apple USB-C Digital AV Multiport Adapter or the newer one or a different HDMI adapter? For the Apple adapters, the model number is printed on the adapter.

https://forums.macrumors.com/threads/3rd-generation-ipad-pro-can-support-simultaneous-4k-60-hz-and-usb-3-0.2193083/

https://support.apple.com/en-us/HT207806


The EDID for your HDMI port is the same as the one from jizmodo except yours is from HDMI port #1 and his was from HDMI port #2. Interesting that they gave have different product IDs even though they don't have any other differences besides the port number.


So far we have 3 product IDs:

a107 = HDMI port #1

a109 = HDMI port #2

a10f = USB-C


I wonder if there are more for this display?


Interesting that the Intel Graphic Control panel allowed the 5120 x 1440 @ 45Hz mode.


I wonder if there's DisplayID info stored outside of the EDID? Accessible using DDC?


I believe source code for Intel graphics drivers exists in Linux. I wonder what it says about maximum width? Has the display been tested in Linux?

Dec 31, 2019 5:56 PM in response to Mister_Highping

Minor correction to previous post https://discussions.apple.com/thread/8641919?answerId=251812380022#251812380022

I had said that Apple rewrote HT202351. Actually what they did was redirected HT206587 to HT202351 and deleted HT206587. You can find HT206587 at https://web.archive.org/web/20191123020413/https://support.apple.com/en-us/HT206587


I created a patch for my Macmini8,1 (macOS Catalina 10.15.2) to allow resolutions greater than 4096 wide but it's not showing an image for timings wider than 4200. I can take screenshots though (I tested up to 5120x900). I'm not sure if the problem is with my adapter or the driver. I only tried 4104 which works. I should try more values to find the exact limit between 4104 and 4200. I could not find a significant difference in the log stream output between switching from 4096 to 4104 and switching from 4096 to 4200. The log stream command was mentioned at https://discussions.apple.com/thread/8641919?answerId=251812762022#251812762022


Before trying the patch, make a backup of /System/Library/Extensions/AppleIntelCFLGraphicsFramebuffer.kext. I think you might need to disable SIP.


sudo mount -uw /
IFS=$'\n'
for thefile in $(find /System/Library/Extensions -name 'AppleIntelCFLGraphicsFramebuffer'); do
	printf "Patching $thefile\n"
	sudo perl -i.bak -pe '$before = qr"(\x83\xc9)\x04(\xC1\xE1\x0A)"s;s/$before/$1\x08$2/g' $thefile
	printf "Re-signing $thefile\n"
	sudo codesign -f -s - $thefile
done
sudo touch /System/Library/Extensions
sudo kextcache -i /


If your Mac doesn't use AppleIntelCFLGraphicsFramebuffer then you might need a different patch. The patch modifies the width check in AppleIntelFramebuffer::ValidateSourceSize(IODetailedTimingInformationV2*). The original check is for 4096 or 5120 for when multilink flag is set. I changed it to 8192 and 9216.


There is a height check for ≤ 2880 pixels near the width check that I did not change.


The function outputs a message to log when the width or height is exceeded:

"[IGFB][INFO   ] FB%d: Mode with width %d and max %d rejected with multilink set to %d\n"


Jan 15, 2020 1:50 AM in response to kanonendk

I'd like to share my experiences here.

I thought about buying this display for a long time, and after reading this topic over and over, I finally decided to do it, even if the full resolution would only be possible with the PbP-"hack".


And I don't regret it at all!


First, my setup:

  • A Dell U4919DW
  • A Macbook Pro 15'' 2017 with Intel HD Graphics 630 1536mb (integrated) + Radeon Pro 555 2GB (dedicated), OS X 10.15.2
  • A Macbook Pro 13'' Mid 2014 with Intel Iris 1536mb (integrated), OS X 10.15.2



First I plugged in the 15'' via the USB-C cable that shipped with the monitor. And it worked OOTB! Full 5120x1440x60 resolution, no upscaling. Just the full native resolution. The macbook got charged automatically and the integrated usb hub worked flawlessly as well. One single cable to the Macbook, that's all. Perfect!



Then I plugged in the 13'' via the HDMI cable that shipped with the display, and a (very cheap, and a few years old) 3rd-party mini-dp to hdmi cable. Turned on the PbP-mode on the monitor, and second success! The monitor renders 2 displays at native 2560x1440x60 each. So in total, there is the full native resolution here too.


Both setups run fine, no problems at all with sleep mode etc. The monitor gets recognized every time without any hassle.

Also, there is absolutely no change on closing the lid oder powering the macbooks. Both macbooks work with lid open/closed and power source connected/disconnected. (The 15'' with usb-c connected does actually charge the macbook as I wrote earlier, so I can't guarantee that it works without it, but I'm fairly sure it should be fine).





However, I see 2 minor downsides on this monitor:

  • Imho the radius is too large for this display. The edges are a bit far away from the eyes. But that's personal preference. Maybe you should go see the monitor somewhere in a store before you decide if you wanna buy it or not.
  • The on-display menu is only accessible if a display source is present. Therefore you have to toggle the PbP mode before you change the input. That is a bit weird, but no problem if you do so.


Apart from this, the monitor is just WOW! Very massive, nice and clean design, no dead pixels at all. Very high quality as usual and expected by Dell.



So the EDID issue was not reproducable, at least for me. But I'm happy to help if you need further specific information regarding my setup!

Dell U4919DW / MacBook pro 5k issue

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.